/*
 * Copyright (c) 2007, 2015, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
/*
 * Copyright 2001-2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id: GetOpt.java,v 1.2.4.1 2005/08/31 11:46:04 pvedula Exp $
 */

package com.sun.org.apache.xalan.internal.xsltc.cmdline.getopt;

import java.util.ArrayList;
import java.util.List;
import java.util.ListIterator;

import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ErrorMsg;


/**
 * GetOpt is a Java equivalent to the C getopt() library function
 * discussed in man page getopt(3C). It provides command line
 * parsing for Java applications. It supports the most rules of the
 * command line standard (see man page intro(1)) including stacked
 * options such as '-sxm' (which is equivalent to -s -x -m); it
 * handles special '--' option that signifies the end of options.
 * Additionally this implementation of getopt will check for
 * mandatory arguments to options such as in the case of
 * '-d <file>' it will throw a MissingOptArgException if the
 * option argument '<file>' is not included on the commandline.
 * getopt(3C) does not check for this.
 *
 * @author G Todd Miller
 */
public class GetOpt {

  public GetOpt(String[] args, String optString) {
    theOptions = new ArrayList();
    int currOptIndex = 0;
    theCmdArgs = new ArrayList();
    theOptionMatcher = new OptionMatcher(optString);
    // fill in the options list
    for (int i = 0; i < args.length; i++) {
      String token = args[i];
      int tokenLength = token.length();
      if (token.equals("--")) {         // end of opts
        currOptIndex = i + 1;         // set index of first operand
        break;                      // end of options
      } else if (token.startsWith("-") && tokenLength == 2) {
        // simple option token such as '-s' found
        theOptions.add(new Option(token.charAt(1)));
      } else if (token.startsWith("-") && tokenLength > 2) {
        // stacked options found, such as '-shm'
        // iterate thru the tokens after the dash and
        // add them to theOptions list
        for (int j = 1; j < tokenLength; j++) {
          theOptions.add(new Option(token.charAt(j)));
        }
      } else if (!token.startsWith("-")) {
        // case 1- there are not options stored yet therefore
        // this must be an command argument, not an option argument
        if (theOptions.size() == 0) {
          currOptIndex = i;
          break;              // stop processing options
        } else {
          // case 2-
          // there are options stored, check to see if
          // this arg belong to the last arg stored
          int indexoflast = 0;
          indexoflast = theOptions.size() - 1;
          Option op = (Option) theOptions.get(indexoflast);
          char opLetter = op.getArgLetter();
          if (!op.hasArg() && theOptionMatcher.hasArg(opLetter)) {
            op.setArg(token);
          } else {
            // case 3 -
            // the last option stored does not take
            // an argument, so again, this argument
            // must be a command argument, not
            // an option argument
            currOptIndex = i;
            break;                  // end of options
          }
        }
      }// end option does not start with "-"
    } // end for args loop

    //  attach an iterator to list of options
    theOptionsIterator = theOptions.listIterator();

    // options are done, now fill out cmd arg list with remaining args
    for (int i = currOptIndex; i < args.length; i++) {
      String token = args[i];
      theCmdArgs.add(token);
    }
  }


  /**
   * debugging routine to print out all options collected
   */
  public void printOptions() {
    for (ListIterator it = theOptions.listIterator(); it.hasNext(); ) {
      Option opt = (Option) it.next();
      System.out.print("OPT =" + opt.getArgLetter());
      String arg = opt.getArgument();
      if (arg != null) {
        System.out.print(" " + arg);
      }
      System.out.println();
    }
  }

  /**
   * gets the next option found in the commandline. Distinguishes
   * between two bad cases, one case is when an illegal option
   * is found, and then other case is when an option takes an
   * argument but no argument was found for that option.
   * If the option found was not declared in the optString, then
   * an IllegalArgumentException will be thrown (case 1).
   * If the next option found has been declared to take an argument,
   * and no such argument exists, then a MissingOptArgException
   * is thrown (case 2).
   *
   * @return int - the next option found.
   * @throws IllegalArgumentException, MissingOptArgException.
   */
  public int getNextOption() throws IllegalArgumentException,
      MissingOptArgException {
    int retval = -1;
    if (theOptionsIterator.hasNext()) {
      theCurrentOption = (Option) theOptionsIterator.next();
      char c = theCurrentOption.getArgLetter();
      boolean shouldHaveArg = theOptionMatcher.hasArg(c);
      String arg = theCurrentOption.getArgument();
      if (!theOptionMatcher.match(c)) {
        ErrorMsg msg = new ErrorMsg(ErrorMsg.ILLEGAL_CMDLINE_OPTION_ERR,
            new Character(c));
        throw (new IllegalArgumentException(msg.toString()));
      } else if (shouldHaveArg && (arg == null)) {
        ErrorMsg msg = new ErrorMsg(ErrorMsg.CMDLINE_OPT_MISSING_ARG_ERR,
            new Character(c));
        throw (new MissingOptArgException(msg.toString()));
      }
      retval = c;
    }
    return retval;
  }

  /**
   * gets the argument for the current parsed option. For example,
   * in case of '-d <file>', if current option parsed is 'd' then
   * getOptionArg() would return '<file>'.
   *
   * @return String - argument for current parsed option.
   */
  public String getOptionArg() {
    String retval = null;
    String tmp = theCurrentOption.getArgument();
    char c = theCurrentOption.getArgLetter();
    if (theOptionMatcher.hasArg(c)) {
      retval = tmp;
    }
    return retval;
  }

  /**
   * gets list of the commandline arguments. For example, in command
   * such as 'cmd -s -d file file2 file3 file4'  with the usage
   * 'cmd [-s] [-d <file>] <file>...', getCmdArgs() would return
   * the list {file2, file3, file4}.
   *
   * @return String[] - list of command arguments that may appear after options and option
   * arguments.
   * @params none
   */
  public String[] getCmdArgs() {
    String[] retval = new String[theCmdArgs.size()];
    int i = 0;
    for (ListIterator it = theCmdArgs.listIterator(); it.hasNext(); ) {
      retval[i++] = (String) it.next();
    }
    return retval;
  }


  private Option theCurrentOption = null;
  private ListIterator theOptionsIterator;
  private List theOptions = null;
  private List theCmdArgs = null;
  private OptionMatcher theOptionMatcher = null;

  ///////////////////////////////////////////////////////////
  //
  //   Inner Classes
  //
  ///////////////////////////////////////////////////////////

  // inner class to model an option
  class Option {

    private char theArgLetter;
    private String theArgument = null;

    public Option(char argLetter) {
      theArgLetter = argLetter;
    }

    public void setArg(String arg) {
      theArgument = arg;
    }

    public boolean hasArg() {
      return (theArgument != null);
    }

    public char getArgLetter() {
      return theArgLetter;
    }

    public String getArgument() {
      return theArgument;
    }
  } // end class Option


  // inner class to query optString for a possible option match,
  // and whether or not a given legal option takes an argument.
  //
  class OptionMatcher {

    public OptionMatcher(String optString) {
      theOptString = optString;
    }

    public boolean match(char c) {
      boolean retval = false;
      if (theOptString.indexOf(c) != -1) {
        retval = true;
      }
      return retval;
    }

    public boolean hasArg(char c) {
      boolean retval = false;
      int index = theOptString.indexOf(c) + 1;
      if (index == theOptString.length()) {
        // reached end of theOptString
        retval = false;
      } else if (theOptString.charAt(index) == ':') {
        retval = true;
      }
      return retval;
    }

    private String theOptString = null;
  } // end class OptionMatcher
}// end class GetOpt
